Organometallic compound, organic light-emitting device including the organometallic compound, and diagnostic composition including the organometallic compound

ABSTRACT

An organometallic compound represented by Formula 1: 
     
       
         
         
             
             
         
       
     
     wherein, in Formula 1, groups and variables are the same as described in the specification.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No. 10-2017-0024923, filed on Feb. 24, 2017, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which is incorporated herein in its entirety by reference.

BACKGROUND 1. Field

One or more embodiments relate to an organometallic compound, an organic light-emitting device including the organometallic compound, and a diagnostic composition including the organometallic compound.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emission devices, which have superior characteristics in terms of a viewing angle, a response time, and a brightness, a driving voltage, and a response speed, and which produce full-color images.

In an example, an organic light-emitting device includes an anode, a cathode, and an organic layer disposed between the anode and the cathode, wherein the organic layer includes an emission layer. A hole transport region may be disposed between the anode and the emission layer, and an electron transport region may be disposed between the emission layer and the cathode. Holes provided from the anode may move toward the emission layer through the hole transport region, and electrons provided from the cathode may move toward the emission layer through the electron transport region. The holes and the electrons recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state, thereby generating light.

Meanwhile, luminescent compounds may be used to monitor, sense, or detect a biological material such as a cell protein. Examples of such luminescent compounds include a phosphorescent luminescent compound.

Various types of organic light emitting devices are known. However, there still remains a need in OLEDs having low driving voltage, high efficiency, high brightness, and long lifespan.

SUMMARY

One or more embodiments include a novel organometallic compound, an organic light-emitting device including the organometallic compound, and a diagnostic composition including the organometallic compound.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

According to one or more embodiments, an organometallic compound is represented by Formula 1:

In Formula 1,

M may be beryllium (Be), magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), zirconium (Zr), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), rhenium (Re), platinum (Pt), or gold (Au),

X₁ may be O or S, and a bond between X₁ and M may be a covalent bond,

X₂ to X₄ may each independently be N or C, and one bond selected from a bond between X₂ and M, a bond between X₃ and M, and a bond between X₄ and M may be a covalent bond, and the others thereof may each be a coordinate bond,

Y₁ to Y₉ may each independently be C or N,

Y₁₀ and Y₁₁ may each independently be C, N, O, or S,

Y₁ and Y₁₀, Y₁ and Y₂, X₂ and Y₃, X₂ and Y₄, Y₄ and Y₅, X₅₁ and Y₃, X₅₁ and Y₅, Y₄ and Y₆, X₃ and Y₇, X₃ and Y₈, X₄ and Y₉, and X₄ and Y₁₁ may each be linked via a chemical bond,

CY₁ to CY₅ may each independently be a C₅-C₃₀ carbocyclic group or a C₁-C₃₀ heterocyclic group,

a cyclometalated ring formed by CY₅, CY₂, CY₃, and M may be a 6-membered ring, a 7-membered ring, or an 8-membered ring,

T₁ to T₃ may each independently be selected from *—N[(L₅)_(b5)-(R₅)]—*′, *—B(R₅)—*′, *—P(R₅)—*′, *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—Ge(R₅)(R₆)—*′, *—S—*′*—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)₂—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═S)—*′, and *—C≡C—*′,

R₅ and R₆ may optionally be linked via a single bond or a first linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

n1 to n3 may each independently be 0, 1, 2, or 3, wherein, when n1 is zero, *-(T₁)_(n1)-*′ may be a single bond, when n2 is zero, *-(T₂)_(n2)-*′ may be a single bond, and when n3 is zero, *-(T₃)_(n3)-*′ may be a single bond,

the sum of n1, n2, and n3 may be one or more,

X₅₁ may be O, S, N[(L₇)_(b7)-(R₇)_(c7)], C[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], Si[(L₇)_(b7)—(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], C(═O), N, C[(L₇)_(b7)-(R₇)_(c7)], or Si[(L₇)_(b7)-(R₇)_(c7)],

R₇ and R₈ may optionally be linked via a single bond or a second linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

L₁ to L₅, L₇, and L₈ may each independently be selected from a single bond, a substituted or unsubstituted C₅-C₃₀ carbocyclic group, and a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

b1 to b5, b7, and b8 may each independently be an integer from 1 to 5,

R₁ to R₈ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),

c1 to c4, c7, and c8 may each independently be an integer from 1 to 5,

a1 to a4 may each independently be an integer from 0 to 20,

two neighboring groups R₁ selected from a plurality of neighboring groups R₁ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two neighboring groups R₂ selected from a plurality of neighboring groups R₂ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two neighboring groups R₃ selected from a plurality of neighboring groups R₃ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two neighboring groups R₄ selected from a plurality of neighboring groups R₄ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

two or more neighboring groups selected from R₁ to R₄ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group,

at least one substituent of the substituted C₅-C₃₀ carbocyclic group, the substituted C₁-C₃₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), and —P(═O)(Q₁₈)(Q₁₉);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉), and

Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkyl group substituted with at least one selected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with at least one selected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.

According to one or more embodiments, an organic light-emitting device includes:

a first electrode;

a second electrode; and

an organic layer disposed between the first electrode and the second electrode, wherein the organic layer includes an emission layer and at least one of the organometallic compound.

The organometallic compound may act as a dopant in the organic layer.

According to one or more embodiments, a diagnostic composition includes at least one of the organometallic compound represented by Formula 1.

BRIEF DESCRIPTION OF THE DRAWING

These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the FIGURE, which is a schematic view of an organic light-emitting device according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

It will be understood that when an element is referred to as being “on” another element, it can be directly in contact with the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the present embodiments.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The term “or” means “and/or.” It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this general inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims.

“About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

In an embodiment, an organometallic compound is provided. The organometallic compound, according to an embodiment, may be represented by Formula 1:

M in Formula 1 may be beryllium (Be), magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), zirconium (Zr), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), rhenium (Re), platinum (Pt), or gold (Au).

In an embodiment, M may be platinum, but embodiments of the present disclosure are not limited thereto.

The organometallic compound represented by Formula 1 may be a neutral compound which does not consist of an ion pair of an anion and a cation.

In Formula 1, X₁ may be O or S; a bond between X₁ and M may be a covalent bond; X₂ to X₄ may each independently be N or C; and one bond selected from a bond between X₂ and M, a bond between X₃ and M, and a bond between X₄ and M may be a covalent bond, and the others thereof may each be a coordinate bond.

For example, in Formula 1,

X₂ may be C, X₃ and X₄ may each be N, a bond between X₂ and M may be a covalent bond, and a bond between X₃ and M and a bond between X₄ and M may each be a coordinate bond;

X₃ may be C, X₂ and X₄ may each be N, a bond X₃ and M may be a covalent bond, and a bond between X₂ and M and a bond between X₄ and M may each be a coordinate bond; or

X₄ may be C, X₂ and X₃ may each be N, a bond between X₄ and M may be a covalent bond, and a bond X₂ and M and a bond between X₃ and M may each be a coordinate bond.

In Formula 1, Y₁ to Y₉ may each independently be C or N; Y₁₀ and Y₁₁ may each independently be C, N, O, or S; and Y₁ and Y₁₀, Y₁ and Y₂, X₂ and Y₃, X₂ and Y₄, Y₄ and Y₅, X₅₁ and Y₃, X₅₁ and Y₅, Y₄ and Y₆, X₃ and Y₇, X₃ and Y₈, X₄ and Y₉, and X₄ and Y₁₁ may each be linked via a chemical bond.

CY₁ to CY₅ in Formula 1 may each independently be a C₅-C₃₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, and a cyclometalated ring formed by CY₅, CY₂, CY₃, and M may be a 6-membered ring, a 7-membered ring, or an 8-membered ring.

For example, CY₁ to CY₄ in Formula 1 may each independently be selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group.

In an embodiment, CY₁ to CY₄ in Formula 1 may each independently be selected from a benzene group, a naphthalene group, a dibenzofuran group, a dibenzothiophene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a quinoline group, an isoquinoline group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, but embodiments of the present disclosure are not limited thereto.

T₁ to T₃ in Formula 1 may each independently be selected from *—N[(L₅)_(b5)—(R₅)]—*′, *—B(R₅)—*′, *—P(R₅)—*′, *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—Ge(R₅)(R₆)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)₂—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═S)—*′, and *—C≡C—*′. L₅, b5, R₅, and R₆ are each independently the same as described below.

R₅ and R₆ may optionally be linked via a single bond or a first linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group.

In an embodiment, T₁ to T₃ in Formula 1 may each independently be selected from *—N[(L₅)_(b5)-(R₅)]—*′, *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—Ge(R₅)(R₆)—*′, *—S—*′, and *—O—*′.

In one or more embodiments, in Formula 1, T₁ to T₃ may each independently be selected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, and R₅ and R₆ may be linked via a single bond or a first linking group. The first linking group may be selected from *—N[(L₉)_(b9)-(R₉)]—*′, *—B(R₉)—*′, *—P(R₉)—*′, *—C(R₉)(R₁₀)—*′, *—Si(R₉)(R₁₀)—*′, *—Ge(R₉)(R₁₀)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)₂—*′, *—C(R₉)═*′, *═C(R₉)—*′, *—C(R₉)═C(R₁₀)—*′, *—O(═S)—*′, and *—C≡C—*′, L₉ and b9 are each independently the same as described in connection with L₅ and b5, R₉ and R₁₀ are each independently the same as described in connection with R₅, and * and *′ each indicate a binding site to a neighboring atom.

n1 to n3 in Formula 1 may each independently be 0, 1, 2, or 3, wherein, when n1 is zero, *-(T₁)_(n1)-*′ may be a single bond; when n2 is zero, *-(T₂)_(n2)-*′ may be a single bond; when n3 is zero, *-(T₃)_(n3)-*′ may be a single bond; and the sum of n1, n2, and n3 may be one or more.

For example, the sum of n1, n2, and n3 may be 1 or 2.

In one or more embodiments, in Formula 1,

n1 may be 1, and n2 and n3 may each be 0;

n2 may be 1, and n1 and n3 may each be 0; or

n3 may be 1, and n1 and n2 may each be 0,

but embodiments of the present disclosure are not limited thereto.

X₅₁ in Formula 1 may be O, S, N[(L₇)_(b7)-(R₇)_(c7)], C[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], Si[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], C(═O), N, C[(L₇)_(b7)-(R₇)_(c7)], or Si[(L₇)_(b7)-(R₇)_(c7)], L₇, L₈, b7, b8, R₇, R₈, c7, and c8 are each independently the same as described below.

R₇ and R₈ may optionally be linked via a single bond or a second linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group. The second linking group is the same as described in connection with the first linking group.

In one or more embodiments, in Formula 1,

i) Y₃ and Y₅ may be C, a bond between X₅₁ and Y₃ and a bond between X₅₁ and Y₅ may each be a single bond, and X₅₁ may be O, S, N[(L₇)_(b7)-(R₇)_(c7)], C[(L₇)_(b7)—(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], Si[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], or C(═O),

ii) Y₃ may be C, Y₅ may be N, a bond between X₅₁ and Y₃ may be a double bond, a bond between X₅₁ and Y₅ may be a single bond, and X₅₁ may be N, C[(L₇)_(b7)—(R₇)_(c7)], or Si[(L₇)_(b7)-(R₇)_(c7)], or

iii) Y₃ may be N, Y₅ may be C, a bond between X₅₁ and Y₃ may be a single bond, a bond between X₅₁ and Y₅ may be a double bond, and X₅₁ may be N, C[(L₇)_(b7)-(R₇)_(c7)], or Si[(L₇)_(b7)-(R₇)_(c7)].

L₁ to L₈, L₇, and L₈ in Formula 1 may each independently be selected from a single bond, a substituted or unsubstituted C₅-C₃₀ carbocyclic group, and a substituted or unsubstituted C₁-C₃₀ heterocyclic group.

For example, L₁ to L₈, L₇, and L₈ in Formula 1 may each independently be selected from:

a single bond, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, and a benzothiadiazole group; and

a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, and a benzothiadiazole group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a fluorenyl group, a dimethylfluorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a dimethyldibenzosilolyl group, a diphenyldibenzosilolyl group, —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉), and

Q₃₁ to Q₃₉ may each independently be selected from:

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDC₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂C₂H, and —CD₂CDH₂;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group.

b1, b2, b3, b4, b5, b7, and b8 in Formula 1 respectively indicate the number of groups L₁, the number of groups L₂, the number of groups L₃, the number of groups L₄, the number of groups L₅, the number of groups L₇, and the number of groups L₈, and may each independently be an integer from 1 to 5. When b1, b2, b3, b4, b5, b7, and b8 are each independently two or more, two or more groups L₁, two or more groups L₂, two or more groups L₃, two or more groups L₄, two or more groups L₅, two or more groups L₇, and two or more groups L₈ may each independently be identical to or different from each other. For example, b1 to b5, b7, and b8 may each independently be 1 or 2.

R₁ to R₈ in Formula 1 may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₅)(Q₉), and Q₁ to Q₉ are each independently the same as described herein.

For example, R₁ to R₈ in Formula 1 may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, —SF₅, C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, and a pyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and —Si(Q₃₃)(Q₃₄)(Q₃₅); and

—N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₅)(Q₉), and

Q₁ to Q₉ and Q₃₃ to Q₃₅ are each independently the same as described herein.

In an embodiment, R₁ to R₈ in Formula 1 may each independently be selected from hydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, groups represented by Formulae 9-1 to 9-19, groups represented by Formulae 10-1 to 10-156, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉) (Q₁ to Q₉ are each independently the same as described herein), but embodiments of the present disclosure are not limited thereto:

In Formulae 9-1 to 9-19 and 10-1 to 10-156, “Ph” indicates a phenyl group, “TMS” indicates a trimethylsilyl group, and * indicates a binding site to a neighboring atom.

c1, c2, c3, c4, c7, and c8 in Formula 1 respectively indicate the number of groups R₁, the number of groups R₂, the number of groups R₃, the number of groups R₄, the number of groups R₇, and the number of groups R₈, and may each independently be an integer from 1 to 5. When c1, c2, c3, c4, c7, and c8 are each independently two or more, two or more groups R₁, two or more groups R₂, two or more groups R₃, two or more groups R₄, two or more groups R₇, and two or more groups R₈ may each independently be identical to or different from each other. For example, c1, c2, c3, c4, c7, and c8 may each independently be 1 or 2.

a1, a2, a3, and a4 in Formula 1 respectively indicate the number of groups *-[(L₁)_(b1)-(R₁)_(c1)], the number of groups *-[(L₂)_(b2)-(R₂)_(c2)], the number of groups *-[(L₃)_(b3)-(R₃)_(c3)], and the number of groups *-[(L₄)_(b4)-(R₄)_(c4)], and may each independently be an integer from 0 to 20. When a1, a2, a3, and a4 are each independently two or more, two or more groups *-[(L₁)_(b1)-(R₁)_(c1)], two or more groups *-[(L₂)_(b2)-(R₂)_(c2)], two or more groups *-[(L₃)_(b3)-(R₃)_(c3)], and two or more groups *-[(L₄)_(b4)-(R₄)_(c4)] may each independently be identical to or different from each other. For example, a1, a2, a3, and a4 may each independently be 1 or 2.

In an embodiment, a moiety represented by

in Formula 1 may be selected from groups represented by Formulae CY1-1 to CY1-26 (for example, groups represented by Formulae CY1-1, CY1-13, CY1-24, and CY1-26):

In Formulae CY1-1 to CY1-26,

Y₁ and R₁ are each independently the same as described herein,

X₁₉ may be C(R_(19a))(R_(19b)), N[(L₁₉)_(b19)-(R₁₉)c₁₉], O, S, or Si(R_(19a))(R_(19b)),

L₁₉, b19, R₁₉, and c19 are each independently the same as described in connection with L₁, b1, R₁, and c1,

R₁₁ to R₁₈, R_(19a), and R_(19b) are each independently the same as described in connection with R₁,

a12 may be an integer from 0 to 2,

a13 may be an integer from 0 to 3,

a14 may be an integer from 0 to 4,

a15 may be an integer from 0 to 5,

a16 may be an integer from 0 to 6, and

* and *′ each indicate a binding site to a neighboring atom.

In one or more embodiments, a moiety represented by

in Formula 1 may be selected from groups represented by Formulae CY2-1 to CY2-12 (for example, a group represented by Formulae CY2-1):

In Formulae CY2-1 to CY2-12,

R₂ is the same as described herein,

X₅₁ in Formulae CY2-1 to CY2-4 may be O, S, N[(L₇)_(b7)-(R₇)_(c7)], C[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], Si[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], or C(═O),

X₅₁ in Formulae CY2-5 to CY2-12 may be N, C[(L₇)_(b7)-(R₇)_(c7)], or Si[(L₇)_(b7)-(R₇)_(c7)],

L₇, L₈, b7, b8, R₇, R₈, c7, and c8 are each independently the same as described herein,

a22 may be an integer from 0 to 2,

a23 may be an integer from 0 to 3, and

*, *′, and *″ each indicate a binding site to a neighboring atom.

In one or more embodiments, a moiety represented by

in Formula 1 may be selected from groups represented by Formulae CY3-1 to CY3-12 (for example, groups represented by Formulae CY3-1, CY3-5, CY3-7, CY3-8, and CY3-12):

In Formulae CY3-1 to CY3-12,

X₃ and R₃ are each independently the same as described herein,

X₃₉ may be C(R_(39a))(R_(39b)), N[(L₃₉)_(b39)-(R₃₉)_(c39)], O, S, or Si(R_(39a))(R_(39b)),

L₃₉, b39, R₃₉, and c39 are each independently the same as described in connection with L₃, b3, R₃, and c3,

R_(39a) and R_(39b) are each independently the same as described in connection with R₃,

a32 may be an integer from 0 to 2,

a33 may be an integer from 0 to 3,

a34 may be an integer from 0 to 4,

a35 may be an integer from 0 to 5, and

*, *′, and *″ each indicate a binding site to a neighboring atom.

In one or more embodiments, a moiety represented by

in Formula 1 may be selected from groups represented by Formulae CY4-1 to CY4-26 (for example, groups represented by Formulae CY4-1 to CY4-5, CY4-9, CY4-11, CY4-18, and CY4-19):

In Formulae CY4-1 to CY4-26,

X₄ and R₄ are each independently the same as described herein,

X₄₉ may be C(R_(49a))(R_(49b)), N[(L₄₉)_(b49)-(R₄₉)_(c49)], O, S, or Si(R_(49a))(R_(49b)),

L₄₉, b49, R₄₉, and c49 are each independently the same as described in connection with L₄, b4, R₄, and c4,

R₄₁ to R₄₈, R_(49a), and R_(49b) are each independently the same as described in connection with R₄,

42 may be an integer from 0 to 2,

a43 may be an integer from 0 to 3,

a44 may be an integer from 0 to 4,

a45 may be an integer from 0 to 5,

a46 may be an integer from 0 to 6, and

* and *′ each indicate a binding site to a neighboring atom.

In one or more embodiments,

a moiety represented by

in Formula 1 may be selected from groups represented by Formulae CY1(1) to CY1(11), and/or

a moiety represented by

in Formula 1 may be selected from groups represented by Formulae CY3(1) to CY3(12), and/or

a moiety represented by

in Formula 1 may be selected from groups represented by Formulae CY4(1) to CY4(19), but embodiments of the present disclosure are not limited thereto:

In Formulae CY1(1) to CY1(11), CY3(1) to CY3(12), and CY4(1) to CY4(19),

X₁₉ may be C(R_(19a))(R_(19b)), N[(L₁₉)_(b19)-(R₁₉)_(c19)], O, S, or Si(R_(19a))(R_(19b)),

X₃₉ may be C(R_(39a))(R_(39b)), N[(L₃₉)_(b39)-(R₃₉)_(c39)], O, S, or Si(R_(39a))(R_(39b)),

Y₁, R₁, X₃, R₃, X₄, and R₄ are each independently the same as described herein,

L₁₉, b19, R₁₉, and c19 are each independently the same as described in connection with L₁, b1, R₁, and c1,

L₃₉, b39, R₃₉, and c39 are each independently the same as described in connection with L₃, b3, R₃, and c3,

R_(1a), R_(1b), R_(19a), and R_(19b) are each independently the same as described in connection with R_(1,)

R_(3a) to R_(3d), R_(39a), and R_(39b) are each independently the same as described in connection with R₃,

R_(4a) to R_(4d) are each independently the same as described in connection with R₄, and

*, *′, and *″ each indicate a binding site to a neighboring atom.

In one or more embodiments, the organometallic compound may be represented by Formula 1-1:

In Formula 1-1,

M, X₁ to X₄, Y₁ to , CY₁ to CY₅, T₁, T₂, n1, n2, X₅₁, L₁ to L₄, b1 to b4, R₁ to R₄, c1 to c4, and a1 to a4 are each independently the same as described herein,

CY₆ and CY₇ may each independently be a C₅-C₃₀ carbocyclic group or a C₃₀ heterocyclic group,

T₄ may be C, Si, or Ge,

T₅ may be selected from a single bond, *—N[(L₉)_(b9)-(R₉)]—*′, *—B(R₉)—*′, *—P(R₉)—*′, *—C(R₉)(R₁₀)—*′, *—Si(R₉)(R₁₀)—*′, *—Ge(R₉)(R₁₀)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)₂—*′, *—C(R₉)═*′, *═C(R₉)—*′, *—C(R₉)═C(R₁₀)—*′, *—C(═S)—*′, and *—C≡C—%′.

L₆₁ and L₇₁ are each independently the same as described in connection with L₁,

b61 and b71 are each independently the same as described in connection with b1,

R₆₁ and R₇₁ are each independently the same as described in connection with R₁,

c61 and c71 are each independently the same as described in connection with c1,

a61 and a71 are each independently the same as described in connection with a1,

L₉, b9, and R₉ are each independently the same as described in connection with L₅, b5, and R₅, and

* and *′ each indicate a binding site to a neighboring atom.

For example, CY₆ and CY₇ may each independently be selected from a benzene group, a naphthalene group, a dibenzofuran group, a dibenzothiophene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a quinoline group, an isoquinoline group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, but embodiments of the present disclosure are not limited thereto.

In Formula 1, i) two neighboring groups R₁ selected from a plurality of neighboring groups R₁ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, ii) two neighboring groups R₂ selected from a plurality of neighboring groups R₂ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, iii) two neighboring groups R₃ selected from a plurality of neighboring groups R₃ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, iv) two neighboring groups R₄ selected from a plurality of neighboring groups R₄ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, and v) two or more neighboring groups selected from R₁ to R₄ may optionally be linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group.

For example, in Formula 1, i) the substituted or unsubstituted C₅-C₃₀ carbocyclic group or the substituted or unsubstituted C₁-C₃₀ heterocyclic group formed by linking two neighboring groups R₁ selected from the plurality of neighboring groups R₁, ii) the substituted or unsubstituted C₅-C₃₀ carbocyclic group or the substituted or unsubstituted C₁-C₃₀ heterocyclic group formed by linking two neighboring groups R₂ selected from the plurality of neighboring groups R₂, iii) the substituted or unsubstituted C₅-C₃₀ carbocyclic group or the substituted or unsubstituted C₁-C₃₀ heterocyclic group formed by linking two neighboring groups R₃ selected from the plurality of neighboring groups R₃, iv) the substituted or unsubstituted C₅-C₃₀ carbocyclic group or the substituted or unsubstituted C₁-C₃₀ heterocyclic group formed by linking two neighboring groups R₄ selected from the plurality of neighboring groups R₄, and v) the substituted or unsubstituted C₅-C₃₀ carbocyclic group or the substituted or unsubstituted C₁-C₃₀ heterocyclic group formed by linking two or more neighboring groups selected from R₁ to R₄ may each independently be selected from:

a pentadiene group, a cyclohexane group, a cycloheptane group, an adamantane group, a bicyclo-heptane group, a bicyclooctane group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a naphthalene group, an anthracene group, a tetracene group, a phenanthrene group, a dihydronaphthalene group, a phenalene group, a benzothiophene group, a benzofuran group, an indene group, an indole group, a benzosilole group, an azabenzothiophene group, an azabenzofuran group, an azaindene group, an azaindole group, and an azabenzosilole group; and

a pentadiene group, a cyclohexane group, a cycloheptane group, an adamantane group, a bicycloheptane group, a bicyclooctane group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a naphthalene group, an anthracene group, a tetracene group, a phenanthrene group, a dihydronaphthalene group, a phenalene group, a benzothiophene group, a benzofuran group, an indene group, an indole group, a benzosilole group, an azabenzothiophene group, an azabenzofuran group, an azaindene group, an azaindole group, and an azabenzosilole group, each substituted with at least one R₁₁,

but embodiments of the present disclosure are not limited thereto.

R₁₁ is the same as described in connection with R₁.

“Azabenzothiophene, azabenzofuran, azaindene, azaindole, azabenzosilole, azadibenzothiophene, azadibenzofuran, azafluorene, azacarbazole, and azadibenzosilole” used herein may mean hetero rings that respectively have the same backbones as “benzothiophene, benzofuran, indene, indole, benzosilole, dibenzothiophene, dibenzofuran, fluorene, carbazole, and dibenzosilole”, provided that at least one ring-forming carbon thereof is substituted with nitrogen.

For example, the organometallic compound may be one of Compounds 1 to 143, but embodiments of the present disclosure are not limited thereto:

The sum of n1, n2, and n3 in Formula 1 is one or more. That is, at least one of *-(T₁)_(n1)-*′, *-(T₂)_(n2)-*′, and *-(T₃)_(n3)-*′ in Formula 1 is not a single bond. Accordingly, in forming a film including the organometallic compound represented by Formula 1, stacking between the organometallic compounds may be prevented, and *-(T₁)_(n1)-*′, *-(T₂)_(n2)-*′, or *-(T₃)_(n3)-*′ that is not a single bond in Formula 1 may act as a self-quenching reduction group. Therefore, an electronic device, for example, an organic light-emitting device, which includes the organometallic compound represented by Formula 1, may have a reduced roll-off ratio and improved efficiency.

Also, Formula 1 essentially includes a 5-membered ring represented by CY₅, and a cyclometalated ring formed by CY₅, CY₂, CY₃, and M in Formula 1 is a 6-membered ring, a 7-membered ring, or an 8-membered ring (not a 5-membered ring). Accordingly, due to removal of ring strain, the organometallic compound may have excellent molecular stability. Therefore, an electronic device, for example, an organic light-emitting device, which includes the organometallic compound, may have excellent durability.

For example, a highest occupied molecular orbital (HOMO) energy level, a lowest unoccupied molecular orbital (LUMO) energy level, a singlet (S₁) energy level, and a triplet (T₁) energy level of each of Compounds 1 to 11 were evaluated by a density functional theory (DFT) method of a Gaussian program (the structure was optimized ata B3LYP, 6-31G(d,p) level). Evaluation results are shown in Table 1.

TABLE 1 S₁ energy T₁ energy Compound HOMO LUMO level level No. (eV) (eV) (eV) (eV) 1 −5.086 −1.682 2.882 2.272 2 −4.736 −1.435 2.783 2.554 3 −4.778 −1.46 2.801 2.439 4 −4.723 −1.439 2.77 2.555 5 −4.991 −1.564 2.877 2.307 6 −4.801 −1.335 2.869 2.576 7 −4.843 −1.385 2.874 2.563 8 −5.019 −1.599 2.867 2.304 9 −4.83 −1.38 2.859 2.571 10 −4.935 −1.545 2.801 2.288 11 −4.757 −1.402 2.761 2.574

From Table 1, it is demonstrated that the organometallic compound represented by Formula 1 has such electrical characteristics that are suitable for use in an electronic device, for example, for use as a dopant for an organic light-emitting device.

Synthesis methods of the organometallic compound represented by Formula 1 may be recognizable by one of ordinary skill in the art by referring to Synthesis Examples provided below.

The organometallic compound represented by Formula 1 is suitable for use in an organic layer of an organic light-emitting device, for example, for use as a dopant in an emission layer of the organic layer. Thus, another aspect of the present disclosure provides an organic light-emitting device that includes:

a first electrode;

a second electrode; and

an organic layer that is disposed between the first electrode and the second electrode,

wherein the organic layer includes an emission layer and at least one organometallic compound represented by Formula 1.

The organic light-emitting device may have, due to the inclusion of an organic layer including the organometallic compound represented by Formula 1, a low driving voltage, high efficiency, high power, high quantum efficiency, a long lifespan, a low roll-off ratio, and excellent color purity.

The organometallic compound of Formula 1 may be used between a pair of electrodes of an organic light-emitting device. For example, the organometallic compound represented by Formula 1 may be included in the emission layer. In this embodiment, the organometallic compound may act as a dopant, and the emission layer may further include a host (that is, an amount of the organometallic compound represented by Formula 1 is smaller than an amount of the host).

The expression “(an organic layer) includes at least one of organometallic compounds” as used herein may include an embodiment in which “(an organic layer) includes identical organometallic compounds represented by Formula 1” and an embodiment in which “(an organic layer) includes two or more different organometallic compounds represented by Formula 1.”

For example, the organic layer may include, as the organometallic compound, only Compound 1. In this embodiment, Compound 1 may be included in an emission layer of the organic light-emitting device. In one or more embodiments, the organic layer may include, as the organometallic compound, Compound 1 and Compound 2. In this embodiment, Compound 1 and Compound 2 may be included in an identical layer (for example, Compound 1 and Compound 2 all may be included in an emission layer).

The first electrode may be an anode, which is a hole injection electrode, and the second electrode may be a cathode, which is an electron injection electrode; or the first electrode may be a cathode, which is an electron injection electrode, and the second electrode may be an anode, which is a hole injection electrode.

In an embodiment, in the organic light-emitting device, the first electrode may be an anode, and the second electrode may be a cathode, and the organic layer may further include a hole transport region disposed between the first electrode and the emission layer and an electron transport region disposed between the emission layer and the second electrode, wherein the hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof, and wherein the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

The term “organic layer” as used herein refers to a single layer and/or a plurality of layers between the first electrode and the second electrode of the organic light-emitting device. The “organic layer” may include, in addition to an organic compound, an organometallic complex including metal.

The FIGURE is a schematic view of an organic light-emitting device 10 according to an embodiment. Hereinafter, the structure of an organic light-emitting device according to an embodiment and a method of manufacturing an organic light-emitting device according to an embodiment will be described in connection with the FIGURE. The organic light-emitting device 10 includes a first electrode 11, an organic layer 15, and a second electrode 19, which are sequentially stacked.

A substrate may be additionally disposed under the first electrode 11 or above the second electrode 19. For use as the substrate, any substrate that is used in general organic light-emitting devices may be used, and the substrate may be a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

In one or more embodiments, the first electrode 11 may be formed by depositing or sputtering a material for forming the first electrode 11 on the substrate. The first electrode 11 may be an anode. The material for forming the first electrode 11 may be selected from materials with a high work function to facilitate hole injection. The first electrode 11 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. The material for forming the first electrode 11 may be an indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), or zinc oxide (ZnO). In one or more embodiments, the material for forming the first electrode 11 may be metal, such as magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).

The first electrode 11 may have a single-layered structure or a multi-layered structure including two or more layers. For example, the first electrode 11 may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode 110 is not limited thereto.

The organic layer 15 is disposed on the first electrode 11.

The organic layer 15 may include a hole transport region, an emission layer, and an electron transport region.

The hole transport region may be disposed between the first electrode 11 and the emission layer.

The hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or any combination thereof.

The hole transport region may include only either a hole injection layer or a hole transport layer. In one or more embodiments, the hole transport region may have a hole injection layer/hole transport layer structure or a hole injection layer/hole transport layer/electron blocking layer structure, which are sequentially stacked in this stated order from the first electrode 11.

When the hole transport region includes a hole injection layer (HIL), the hole injection layer may be formed on the first electrode 11 by using one or more suitable methods, for example, vacuum deposition, spin coating, casting, and/or Langmuir-Blodgett (LB) deposition.

When a hole injection layer is formed by vacuum deposition, the deposition conditions may vary according to a material that is used to form the hole injection layer, and the structure and thermal characteristics of the hole injection layer. For example, the deposition conditions may include a deposition temperature of about 100° C. to about 500° C., a vacuum pressure of about 10⁻⁸ torr to about 10⁻³ torr, and a deposition rate of about 0 Å/sec to about 100 Å/sec. However, the deposition conditions are not limited thereto.

When the hole injection layer is formed using spin coating, coating conditions may vary according to the material used to form the hole injection layer, and the structure and thermal properties of the hole injection layer. For example, a coating speed may be from about 2,000 revolutions per minute (rpm) to about 5,000 rpm, and a temperature at which a heat treatment is performed to remove a solvent after coating may be from about 80° C. to about 200° C. However, the coating conditions are not limited thereto.

Conditions for forming a hole transport layer and an electron blocking layer may be understood by referring to conditions for forming the hole injection layer.

The hole transport region may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB, β-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzene sulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrene sulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrene sulfonate) (PANI/PSS), a compound represented by Formula 201 below, and a compound represented by Formula 202 below:

Ar₁₀₁ to Ar₁₀₂ in Formula 201 may each independently be selected from:

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an acenaphthylene group, a fluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, and a pentacenylene group; and

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an acenaphthylene group, a fluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, and a pentacenylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.

xa and xb in Formula 201 may each independently be an integer from 0 to 5, or 0, 1 or 2. For example, xa may be 1 and xb may be 0, but xa and xb are not limited thereto.

R₁₀₁ to R₁₀₈, R₁₁₁ to R₁₁₉, and R₁₂₁ to 8124 in Formulae 201 and 202 may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group (for example, a methyl group, an ethyl group, a propyl group, a butyl group, pentyl group, a hexyl group, or the like), and a C₁-C₁₀ alkoxy group (for example, a methoxy group, an ethoxy group, a propoxy group, butoxy group, a pentoxy group, or the like); a C₁-C₁₀ alkyl group and a C₁-C₁₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof and a phosphoric acid group or a salt thereof;

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, and a pyrenyl group; and

a naphthyl group, an anthracenyl group, a fluorenyl group, and a pyrenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, and a C₁-C₁₀ alkoxy group; but embodiments of the present disclosure are not limited thereto.

R₁₀₉ in Formula 201 may be selected from:

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinyl group; and

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinyl group.

In an embodiment, the compound represented by Formula 201 may be represented by Formula 201A, but embodiments of the present disclosure are not limited thereto:

R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉ in Formula 201A are the same as described above.

For example, the compound represented by Formula 20, and the compound represented by Formula 202 may include compounds HT1 to HT20 illustrated below, but are not limited thereto.

A thickness of the hole transport region may be in a range of about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one of a hole injection layer and a hole transport layer, a thickness of the hole injection layer may be in a range of about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. While not wishing to be bound by theory, it is understood that when the thicknesses of the hole transport region, the hole injection layer and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant. The p-dopant may be one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound, but embodiments of the present disclosure are not limited thereto. Non-limiting examples of the p-dopant are a quinone derivative, such as tetracyanoquinonedimethane (TCNQ) or 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ); a metal oxide, such as a tungsten oxide or a molybdenium oxide; and a cyano group-containing compound, such as Compound HT-D1 below, but are not limited thereto.

The hole transport region may include a buffer layer.

Also, the buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, and thus, efficiency of a formed organic light-emitting device may be improved.

Then, an emission layer (EML) may be formed on the hole transport region by vacuum deposition, spin coating, casting, LB deposition, or the like. When the emission layer is formed by vacuum deposition or spin coating, the deposition or coating conditions may be similar to those applied to form the hole injection layer although the deposition or coating conditions may vary according to the material that is used to form the emission layer.

Meanwhile, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be selected from materials for the hole transport region described above and materials for a host to be explained later. However, the material for the electron blocking layer is not limited thereto. For example, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be mCP, which will be explained later.

The emission layer may include a host and a dopant, and the dopant may include the organometallic compound represented by Formula 1.

The host may include at least one selected from TPBi, TBADN, ADN (also referred to as “DNA”), CBP, CDBP, TCP, mCP, Compound H50, and Compound H51:

In one or more embodiments, the host may further include a compound represented by Formula 301 below.

Ar₁₁₁ to Ar₁₁₂ in Formula 301 may each independently be selected from:

a phenylene group, a naphthylene group, a phenanthrenylene group, and a pyrenylene group; and

a phenylene group, a naphthylene group, a phenanthrenylene group, and a pyrenylene group, each substituted with at least one selected from a phenyl group, a naphthyl group, and an anthracenyl group.

Ar₁₁₃ to Ar₁₁₆ in Formula 301 may each independently be selected from:

a C₁-C₁₀ alkyl group, a phenyl group, a naphthyl group, a phenanthrenyl group, and a pyrenyl group; and

a phenyl group, a naphthyl group, a phenanthrenyl group, and a pyrenyl group, each substituted with at least one selected from a phenyl group, a naphthyl group, and an anthracenyl group.

g, h, i, and j in Formula 301 may each independently be an integer from 0 to 4, and may be, for example, 0, 1, or 2.

Ar₁₁₃ to Ar₁₁₆ in Formula 301 may each independently be selected from:

a C₁-C₁₀ alkyl group, substituted with at least one selected from a phenyl group, a naphthyl group, and an anthracenyl group;

a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl, a phenanthrenyl group, and a fluorenyl group;

a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, and a fluorenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, and a fluorenyl group; and

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the host may include a compound represented by Formula 302:

Ar₁₂₂ to Ar₁₂₅ in Formula 302 are the same as described in detail in connection with Ar₁₁₃ in Formula 301.

Ar₁₂₆ and Ar₁₂₇ in Formula 302 may each independently be a C₁-C₁₀ alkyl group (for example, a methyl group, an ethyl group, or a propyl group).

k and l in Formula 302 may each independently be an integer from 0 to 4. For example, k and l may be 0, 1, or 2.

The compound represented by Formula 301 and the compound represented by Formula 302 may include Compounds H1 to H42 illustrated below, but are not limited thereto.

When the organic light-emitting device is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and a blue emission layer. In one or more embodiments, due to a stack structure including a red emission layer, a green emission layer, and/or a blue emission layer, the emission layer may emit white light.

When the emission layer includes a host and a dopant, an amount of the dopant may be in a range of about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host, but embodiments of the present disclosure are not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. While not wishing to be bound by theory, it is understood that when the thickness of the emission layer is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.

Then, an electron transport region may be disposed on the emission layer.

The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

For example, the electron transport region may have a hole blocking layer/electron transport layer/electron injection layer structure or an electron transport layer/electron injection layer structure, but the structure of the electron transport region is not limited thereto. The electron transport layer may have a single-layered structure or a multi-layered structure including two or more different materials.

Conditions for forming the hole blocking layer, the electron transport layer, and the electron injection layer which constitute the electron transport region may be understood by referring to the conditions for forming the hole injection layer.

When the electron transport region includes a hole blocking layer, the hole blocking layer may include, for example, at least one of BCP, Bphen, and BAlq but embodiments of the present disclosure are not limited thereto:

A thickness of the hole blocking layer may be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. While not wishing to be bound by theory, it is understood that when the thickness of the hole blocking layer is within these ranges, the hole blocking layer may have excellent hole blocking characteristics without a substantial increase in driving voltage.

The electron transport layer may further include at least one selected from BCP, Bphen, Alq₃, BAlq, TAZ, and NTAZ.

In one or more embodiments, the electron transport layer may include at least one of ET1 and ET25, but a material to be included in the electron transport layer is not limited thereto:

A thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. While not wishing to be bound by theory, it is understood that when the thickness of the electron transport layer is within the range described above, the electron transport layer may have satisfactory electron transport characteristics without a substantial increase in driving voltage.

Also, the electron transport layer may further include, in addition to the materials described above, a metal-containing material.

The metal-containing material may include a L₁ complex. The L₁ complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) or ET-D2.

The electron transport region may include an electron injection layer (EIL) that promotes flow of electrons from the second electrode 19 thereinto.

The electron injection layer may include at least one selected from LiF, NaCl, CsF, Li₂O, and BaO.

A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. While not wishing to be bound by theory, it is understood that when the thickness of the electron injection layer is within the range described above, the electron injection layer may have satisfactory electron injection characteristics without a substantial increase in driving voltage.

The second electrode 19 is disposed on the organic layer 15. The second electrode 19 may be a cathode. A material for forming the second electrode 19 may be metal, an alloy, an electrically conductive compound, and a combination thereof, which have a relatively low work function. For example, lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag) may be formed as the material for forming the second electrode 19. To manufacture a top-emission type light-emitting device, a transmissive electrode formed using ITO or IZO may be used as the second electrode 19.

Hereinbefore, the organic light-emitting device has been described with reference to the FIGURE, but embodiments of the present disclosure are not limited thereto.

Another aspect provides a diagnostic composition including at least one organometallic compound represented by Formula 1.

The organometallic compound represented by Formula 1 provides high luminescent efficiency. Accordingly, a diagnostic composition including the organometallic compound may have high diagnosis efficiency.

The diagnostic composition may be used in various applications including a diagnosis kit, a diagnosis reagent, a biosensor, and a biomarker.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear or branched saturated aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an iso-amyl group, and a hexyl group. The term “C₁-C₆₀ alkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₆₀ alkyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalent group represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group), and examples thereof include a methoxy group, an ethoxy group, and an iso-propyloxy group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbon group formed by including at least one carbon-carbon double bond in the middle or at the terminus of the C₂-C₆₀ alkyl group, and examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbon group formed by including at least one carbon-carbon triple bond in the middle or at the terminus of the C₂-C₆₀ alkyl group, and examples thereof include an ethynyl group, and a propynyl group. The term “C₂-C₆₀ alkynylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀ alkynyl group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term “C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to a monovalent saturated monocyclic group having at least one heteroatom selected from N, O, P, Si and S as a ring-forming atom and 1 to 10 carbon atoms, and non-limiting examples thereof include a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to a monovalent monocyclic group that has 3 to 10 carbon atoms, at least one carbon-carbon double bond in the ring thereof, and no aromaticity, and non-limiting examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to a monovalent monocyclic group that has at least one heteroatom selected from N, O, P, Si, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one carbon-carbon double bond in its ring. Examples of the C₁-C₁₀ heterocycloalkenyl group are a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylene group” as used herein refers to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and a C₆-C₆₀ arylene group used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each include two or more rings, the rings may be fused to each other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system that has at least one heteroatom selected from N, O, P, and S as a ring-forming atom, and 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used herein refers to a divalent group having a carbocyclic aromatic system that has at least one heteroatom selected from N, O, P, and S as a ring-forming atom, and 1 to 60 carbon atoms. Non-limiting examples of the C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each include two or more rings, the rings may be fused to each other.

The term “C₆-C₆₀ aryloxy group” used herein indicates —OA₁₀₂ (wherein A₁₀₂ is the C₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group used herein indicates —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group,” used herein, refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group (for example, having 2 to 60 carbon atoms) having two or more rings condensed to each other, a heteroatom selected from N, O, P, Si, and S, other than carbon atoms, as a ring-forming atom, and no aromaticity in its entire molecular structure. Non-limiting examples of the monovalent non-aromatic condensed heteropolycyclic group include a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₅-C₃₀ carbocyclic group” as used herein refers to a saturated or unsaturated cyclic group having, as a ring-forming atom, 5 to 30 carbon atoms only. The C₅-C₃₀ carbocyclic group may be a monocyclic group or a polycyclic group.

The term “C₁-C₃₀ heterocyclic group” as used herein refers to a saturated or unsaturated cyclic group having, as a ring-forming atom, at least one heteroatom selected from N, O, Si, P, and S other than 1 to 30 carbon atoms. The C₁-C₃₀ heterocyclic group may be a monocyclic group or a polycyclic group.

At least one substituent of the substituted C₅-C₃₀ carbocyclic group, the substituted C₂-C₃₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), and —P(═O)(Q₁₈)(Q₁₉);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉);

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉); and

Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with at least one selected from a C₁-C₆₀ alkyl group and a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.

Hereinafter, a compound and an organic light-emitting device according to embodiments are described in detail with reference to Synthesis Example and Examples. However, the organic light-emitting device is not limited thereto. The wording “B was used instead of A” used in describing Synthesis Examples means that an amount of A used was identical to an amount of B used, in terms of a molar equivalent.

EXAMPLES Synthesis Example 1 Synthesis of Compound 1

Synthesis of Intermediate 1-A (N-([1,1′-biphenyl]-2-yl)pyridin-2-amine)

84 grams (g) (496 millimoles, mmol) of [1,1′-biphenyl]-2-amine and 85 g (496 mmol, 1.0 equivalents, equiv.) of 2-bromopyridine were added to a flask, and 143 g (1.5 mol, 3 equiv.) of sodium tert-butoxide, 23 g (0.05 equiv.) of Pd₂(dba)₃, and 5 g (0.08 equiv.) of tri-t-butyl phosphine ((t-Bu)₃P) were added thereto. Then, 800 milliliters (mL) of toluene was added thereto, and the resultant mixture was refluxed at a temperature of 100° C. overnight. The resultant mixture thus obtained was cooled to room temperature, and a precipitate was filtered therefrom. A filtrate obtained therefrom was washed by using ethyl acetate (EA)/H₂O and purified by column chromatography to obtain 37 g (yield: 31%) of Intermediate 1-A. The obtained product was confirmed by Mass and HPLC analysis.

HRMS (MALDI) calcd for C₁₇H₁₄N₂: m/z 246.1157, Found: 246.1154.

Synthesis of Intermediate 1-B N-([1,1′-biphenyl]-2-yl)-N-(3-bromophenyl)pyridin-2-amine

37 g (150 mmol) of Intermediate 1-A and 42 g (150 mmol, 1 equiv.) of 1-bromo-3-iodobenzene were added to a flask, and 43 g (450 mmol, 3 equiv.) of sodium tert-butoxide, 6.8 g (0.05 equiv.) of Pd₂(dba)₃, and 1.5 g (0.08 equiv.) of tri-t-butyl phosphine were added thereto. Then, 500 mL of toluene was added thereto, and the resultant mixture was refluxed at a temperature of 100° C. overnight. The resultant mixture thus obtained was cooled to room temperature, and a precipitate was filtered therefrom. A filtrate obtained therefrom was washed by using EA/H₂O and purified by column chromatography to obtain 36 g (yield: 60%) of Intermediate 1-B. The obtained product was confirmed by Mass and HPLC analysis.

HRMS (MALDI) calcd for C₂₃H₁₇BrN₂: m/z 400.0575, Found: 400.0577.

Synthesis of Intermediate 1-C N-([1,1′-biphenyl]-2-yl)-N-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyridin-2-amine

36 g (90 mmol) of Intermediate 1-B and 34 g (135 mmol, 1.5 equiv.) of bispinacolato diboron were added to a flask, and 18 g (179 mmol, 2 equiv.) of potassium acetate and 3.6 g (4 mmol, 0.05 equiv.) of PdCl₂(dppf) were added thereto. Then, 200 mL of toluene was added thereto, and the resultant mixture was refluxed at a temperature of 100° C. overnight. The resultant mixture thus obtained was cooled to room temperature, and a precipitate was filtered therefrom. A filtrate obtained therefrom was washed by using EA/H₂O and purified by column chromatography to obtain 24 g (yield: 60%) of Intermediate 1-C. The obtained product was confirmed by Mass and HPLC analysis.

HRMS (MALDI) calcd for C₂₉H₂₉BN₂O₂: m/z 448.2322, Found: 448.2321.

Synthesis of Intermediate 1-E 2-(4-(3-([1,1′-biphenyl]-2-yl(pyridin-2-yl)amino)phenyl)benzo[d]thiazol-2-yl)phenol

2.4 g of Intermediate 1-C, 1.5 g (0.005 mol, 1 equiv.) of Intermediate 1-D (2-(4-bromobenzo[d]thiazol-2-yl)phenol), 0.4 g (0.001 mol, 0.07 equiv.) of tetrakis(triphenylphosphine)palladium(0), and 2 g (0.015 mol, 3 equiv.) of potassium carbonate were mixed with 40 mL of a solvent in which tetrahydrofuran (THF) and distilled water (H₂O) were mixed at a ratio of 3:1, and then refluxed for 12 hours. The resultant mixture thus obtained was cooled to room temperature, and a precipitate was filtered therefrom. A filtrate obtained therefrom was washed by using EA/H₂O and purified by column chromatography (eluent:EA/Hex (hexane) 20%˜35%) to obtain 2.0 g (yield: 78%) of Intermediate 1-E. The obtained product was confirmed by Mass and HPLC analysis.

HRMS (MALDI) calcd for C₃₆H₂₅N₃OS: m/z 547.1718, Found: 547.1716.

Synthesis of Compound 1

2 g (3.6 mmol) of Intermediate 1-E and 1.5 g (3.6 mmol, 1.0 equiv.) of K₂PtCl₄ were mixed with 55 mL of a solvent in which 50 mL of AcOH and 5 mL of H₂O were mixed, and then refluxed for 16 hours. The resultant mixture thus obtained was cooled to room temperature, and a precipitate was filtered therefrom. The precipitate was dissolved again in methylene chloride (MC), washed by using H₂O, and purified by column chromatography (MC 35%, Hex 65%) to obtain 0.8 g (purity: 99% or more) of Compound 1. The obtained product was confirmed by Mass and HPLC analysis.

HRMS (MALDI) calcd for C₃₆H₂₃N₃OPtS: m/z 740.1210, Found: 740.1212.

Synthesis Example 2 Synthesis of Compound 2

Synthesis of Intermediate 2-H (N-([1,1′-biphenyl]-2-yl)pyridin-2-amine)

1.5 g (0.005 mol) of Intermediate 2-F (2-(4-bromo-1-methyl-1H-benzo[d]imidazol-2-yl)phenol), 3.6 g (0.006 mol, 1.2 equiv.) of Intermediate 2-G (2-(3′,5′-di-tert-butyl-5-(naphthalen-1-yl(pyridin-2-yl)amino)-[1,1′-biphenyl]-3-yl)-4,5,5-trimethyl-1,3,2-dioxaborolan-4-yl)methylium), 0.4 g (0.001 mol, 0.07 equiv.) of tetrakis(triphenylphosphine)palladium(0), and 2 g (0.015 mol, 3 equiv.) of potassium carbonate were mixed with 40 mL of a solvent in which THF and distilled water (H₂O) were mixed at a ratio of 3:1, and then refluxed for 12 hours. The resultant mixture thus obtained was cooled to room temperature, and a precipitate was filtered therefrom. A filtrate obtained therefrom was washed by using EA/H₂O and purified by column chromatography (eluent: EA/Hex 20%˜35%) to obtain 2.4 g (yield: 70%) of Intermediate 2-H. The obtained product was confirmed by Mass and HPLC analysis.

HRMS (MALDI) calcd for C₄₉H₄₆N₄O: m/z 706.3672, Found: 706.3670.

Synthesis of Compound 2

2.4 g (3.6 mmol) of Intermediate 2-H and 1.4 g (3.4 mmol, 1.0 equiv.) of K₂PtCl₄ were mixed with 55 mL of a solvent in which 50 mL of AcOH and 5 mL of H₂O were mixed, and then refluxed for 16 hours. The resultant mixture thus obtained was cooled to room temperature, and a precipitate was filtered therefrom. The precipitate was dissolved again in MC, washed using H₂O, and purified by column chromatography (MC 35%, Hex 65%) to obtain 0.8 g (purity: 99% or more) of Compound 2. The obtained product was confirmed by Mass and HPLC analysis.

HRMS (MALDI) calcd for C₄₉H₄₄N₄OPt: m/z 899.3163, Found: 899.3165.

Evaluation Example 1 Evaluation of Photoluminescence Quantum Yield (PLQY)

A CH₂Cl₂ solution of polymethyl methacrylate (PMMA) and a mixture of 8 percent by weight (wt %) of CBP and Compound 1 (an amount of Compound 1 was 10 parts by weight based on 100 parts by weight of the mixture) were mixed. The resultant mixture thus obtained was coated on a quartz substrate by using a spin coater, thermally treated at a temperature of 80° C. in an oven, and then cooled to room temperature, thereby completing the manufacture of Film 1.

Photoluminescence quantum yields in Film 1 were evaluated by using a Hamamatsu Photonics absolute PL quantum yield measurement system equipped with a xenon light source, a monochromator, a photonic multichannel analyzer, and an integrating sphere, and using PLQY measurement software (Hamamatsu Photonics, Ltd., Shizuoka, Japan). It was determined that PLQY in a film of Compound 1 was 0.998. Accordingly, it can be determined that Compound 1 has high PLQY in a film.

Example 1

An ITO glass substrate was cut to a size of 50 mm×50 mm×0.5 mm (mm=millimeters), sonicated with acetone, iso-propyl alcohol, and pure water each for 15 minutes, and then cleaned by exposure to ultraviolet (UV) rays and ozone for 30 minutes.

Then, m-MTDATA was deposited on an ITO electrode (anode) of the ITO glass substrate at a deposition rate of 1 Angstroms per second (Å/sec) to form a hole injection layer having a thickness of 600 Å, and α-NPD was deposited on the hole injection layer at a deposition rate of 1 Å/sec to form a hole transport layer having a thickness of 250 Å.

Compound 1 (dopant) and CBP (host) were respectively co-deposited on the hole transport layer at deposition rates of 0.1 Å/sec and 1 Å/sec to form an emission layer having a thickness of 400 Å.

BAlq was deposited on the emission layer at a deposition rate of 1 Å/sec to form a hole blocking layer having a thickness of 50 Å, Alq₃ was deposited on the hole blocking layer to form an electron transport layer having a thickness of 300 Å, LiF was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and Al was vacuum-deposited on the electron injection layer to form a second electrode (cathode) having a thickness of 1,200 Å, thereby ITO/m-MTDATA (600 Å)/α-NPD (250 Å)/CBP+Compound 1 (10%) (400 Å)/BAlq (50 Å)/Alq₃ (300 Å)/LiF (10 Å)/Al (1,200 Å).

Example 2 and Comparative Example A and B

Organic light-emitting devices were manufactured in the same manner as in Example 1, except that Compounds shown in Table 2 were each used instead of Compound 1 as a dopant in forming an emission layer.

Evaluation Example 2 Evaluation of Characteristics of Organic Light-Emitting Devices

The driving voltage, emission efficiency, and PLQY of the organic light-emitting devices manufactured according to Examples 1 and 2 and Comparative Examples A were evaluated. Results are shown in Table 2. This evaluation was performed by using a current-voltage meter (Keithley 2400) and a luminance meter (Minolta Cs-1,000A).

TABLE 2 Driving Emission voltage Efficiency Dopant (V) (cd/A) PLQY (%) Example 1 Compound 1 4.38 69.4 20.2 Example 2 Compound 2 4.37 67.7 19.5 Comparative Compound A 4.57 49.2 18.7 Example A Comparative Compound B 4.0 60.2 15.3 Example B

Referring to Table 2, it is found that the organic light-emitting devices of Examples 1 and 2 have excellent or equivalent driving voltage, emission efficiency, and PLQY, as compared with those of the organic light-emitting devices of Comparative Examples A and B.

Since the organometallic compound has excellent electrical characteristics and thermal stability, an organic light-emitting device including the organometallic compound has excellent driving voltage, efficiency, power, color purity, and lifespan characteristics. Also, since the organometallic compound has excellent phosphorescence characteristics, a diagnostic composition having high diagnostic efficiency may be provided by using the organometallic compound.

It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.

While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims. 

What is claimed is:
 1. An organometallic compound represented by Formula 1:

wherein, in Formula 1, M is beryllium (Be), magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), zirconium (Zr), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), rhenium (Re), platinum (Pt), or gold (Au), X₁ is O or S, and a bond between X₁ and M is a covalent bond, X₂ to X₄ are each independently N or C, and one bond selected from a bond between X₂ and M, a bond between X₃ and M, and a bond between X₄ and M is a covalent bond, and the others thereof are each a coordinate bond, Y₁ to Y₉ are each independently C or N, Y₁₀ and Y₁₁ are each independently C, N, O, or S, Y₁ and Y₁₀, Y₁ and Y₂, X₂ and Y₃, X₂ and Y₄, Y₄ and Y₅, X₅₁ and Y₃, X₅₁ and Y₅, Y₄ and Y₆, X₃ and Y₇, X₃ and Y₈, X₄ and Y₉, and X₄ and Y₁₁ are each linked via a chemical bond, CY₁ to CY₅ are each independently a C₅-C₃₉ carbocyclic group or a C₁-C₃₀ heterocyclic group, a cyclometalated ring formed by CY₅, CY₂, CY₃, and M is a 6-membered ring, a 7-membered ring, or an 8-membered ring, T₁ to T₃ are each independently selected from *—N[(L₅)_(b5)-(R₅)]—*′, *—B(R₅)—*′, *—P(R₅)—*′, *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—Ge(R₅)(R₆)—*′, *—S—*′*—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)₂—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═S)—*′, and *—C≡C—*′, R₅ and R₆ are optionally linked via a single bond or a first linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, n1 to n3 are each independently 0, 1, 2, or 3, wherein, when n1 is zero, *-(T₁)_(n1)-*′ is a single bond, when n2 is zero, *-(T₂)_(n2)-*′ is a single bond, and when n3 is zero, *-(T₃)_(n3)-*′ is a single bond, the sum of n1, n2, and n3 is one or more, X₅₁ is O, S, N[(L₇)_(b7)-(R₇)_(c7)], C[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], Si[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8), C(═O), N, C[(L₇)_(b7)-(R₇)_(c7)], or Si[(L₇)_(b7)-(R₇)_(c7)], R₇ and R₈ are optionally linked via a single bond or a second linking group to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, L₁ to L₈, L₇, and L₈ are each independently selected from a single bond, a substituted or unsubstituted C₅-C₃₀ carbocyclic group, and a substituted or unsubstituted C₁-C₃₀ heterocyclic group, b1 to b5, b7, and b8 are each independently an integer from 1 to 5, R₁ to R₈ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉), c1 to c4, c7, and c8 are each independently an integer from 1 to 5, a1 to a4 are each independently an integer from 0 to 20, two neighboring groups R₁ selected from a plurality of neighboring groups R₁ are optionally linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two neighboring groups R₂ selected from a plurality of neighboring groups R₂ are optionally linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two neighboring groups R₃ selected from a plurality of neighboring groups R₃ are optionally linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two neighboring groups R₄ selected from a plurality of neighboring groups R₄ are optionally linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, two neighboring groups selected from R₁ to R₄ are optionally linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, at least one substituent of the substituted C₅-C₃₀ carbocyclic group, the substituted C₁-C₃₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), and —P(═O)(Q₁₈)(Q₁₉); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉); and —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉), and Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkyl group substituted with at least one selected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with at least one selected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.
 2. The organometallic compound of claim 1, wherein X₂ is C, X₃ and X₄ are each N, a bond between X₂ and M is a covalent bond, and a bond between X₃ and M and a bond between X₄ and M are each a coordinate bond; X₃ is C, X₂ and X₄ are each N, a bond between X₃ and M is a covalent bond, and a bond between X₂ and M and a bond between X₄ and M are each a coordinate bond; or X₄ is C, X₂ and X₃ are each N, a bond between X₄ and M is a covalent bond, and a bond between X₂ and M and a bond between X₃ and M are each a coordinate bond.
 3. The organometallic compound of claim 1, wherein CY₁ to CY₄ are each independently selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group.
 4. The organometallic compound of claim 1, wherein T₁ to T₃ are each independently selected from *—N[(L₅)_(b5)-(R₅)]—*′, *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—Ge(R₅)(R₆)—*′, *—S—*′, and *—O—*′.
 5. The organometallic compound of claim 1, wherein T₁ to T₃ are each independently selected from *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, and *—Ge(R₅)(R₆)—*′, R₅ and R₆ are linked via a single bond or a first linking group, the first linking group is selected from *—N[(L₉)_(b9)-(R₉)]—*′, *—B(R₉)—*′, *—P(R₉)—*′, *—C(R₉)(R₁₀)—*′, *—Si(R₉)(R₁₀)—*′, *—Ge((R₉)(R₁₀)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)₂—*′, *—C(R₉)═*′, *═C(R₉)—*′, *—C(R₉)═C(R₁₀)—*′, *—C(═S)—*′, and *—C≡C—*′, L₉ and b9 are each independently the same as described in connection with L₅ and b5 in claim 1, R₉ and R₁₀ are each independently the same as described in connection with R₅ in claim 1, and * and *′ each indicate a binding site to a neighboring atom.
 6. The organometallic compound of claim 1, wherein n1 is 1, and n2 and n3 are each 0; n2 is 1, and n1 and n3 are each 0; or n3 is 1, and n1 and n2 are each
 0. 7. The organometallic compound of claim 1, wherein R₁ to R₅ are each independently selected from: hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, —SF₅, C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Br, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, and a pyrimidinyl group; a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group; a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and —Si(Q₃₃)(Q₃₄)(Q₃₅); and —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉), and Q₁ to Q₉ and Q₃₃ to Q₃₅ are each independently selected from: —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDC₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂C₂H, and —CD₂CDH₂; an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C₁-C₁₀ alkyl group, and a phenyl group.
 8. The organometallic compound of claim 1, wherein R₁ to R₈ are each independently selected from hydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, groups represented by Formulae 9-1 to 9-19, groups represented by Formulae 10-1 to 10-156, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Qe)(Q₇), and —P(═O)(Q₈)(Q₉):

wherein, in Formulae 9-1 to 9-19 and 10-1 to 10-156, “Ph” indicates a phenyl group, “TMS” indicates a trimethylsilyl group, and * indicates a binding site to a neighboring atom.
 9. The organometallic compound of claim 1, wherein a moiety represented by

in Formula 1 is selected from groups represented by Formulae CY1-1 to CY1-26:

wherein, in Formulae CY1-1 to CY1-26, Y₁ and R₁ are each independently the same as described in claim 1, X₁₉ is C(R_(19a))(R_(19b)), N[(L₁₉)_(b19)-(R₁₉)_(c19)], O, S, or Si(R_(19a))(R_(19b)), L₁₉, b19, R₁₉, and c19 are each independently the same as described in connection with L₁, b1, R₁, and c1 in claim 1, R₁₁ to R₁₈, R_(19a), and R_(19b) are each independently the same as described in connection with R₁ in claim 1, a12 is an integer from 0 to 2, a13 is an integer from 0 to 3, a14 is an integer from 0 to 4, a15 is an integer from 0 to 5, a16 is an integer from 0 to 6, and * and *′ each indicate a binding site to a neighboring atom.
 10. The organometallic compound of claim 1, wherein a moiety represented by

in Formula 1 is selected from groups represented by Formulae CY2-1 to CY2-12:

wherein, in Formulae CY2-1 to CY2-12, R₂ is the same as described in claim 1, X₅₁ in Formulae CY2-1 to CY2-4 is O, S, N[(L₇)_(b7)-(R₇)_(c7)], C[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], Si[(L₇)_(b7)-(R₇)_(c7)][(L₈)_(b8)-(R₈)_(c8)], or C(═O), X₅₁ in Formulae CY2-5 to CY2-12 is N, C[(L₇)_(b7)-(R₇)_(c7)], or Si[(L₇)_(b7)-(R₇)_(c7)], L₇, L₈, b7, b8, R₇, R₈, c7, and c8 are each independently the same as described in claim 1, a22 is an integer from 0 to 2, a23 is an integer from 0 to 3, and *, *′, and *″ each indicate a binding site to a neighboring atom.
 11. The organometallic compound of claim 1, wherein a moiety represented by

in Formula 1 is selected from groups represented by Formulae CY3-1 to CY3-12:

wherein, in Formulae CY3-1 to CY3-12, X₃ and R₃ are each independently the same as described in claim 1, X₃₉ is C(R_(39a))(R_(39b)), N[(L₃₉)_(b39)-(R₃₉)_(c39)], O, S, or Si(R_(39a))(R_(39b)), L₃₉, b39, R₃₉, and c39 are each independently the same as described in connection with L₃, b3, R₃, and c3 in claim 1, R_(39a) and R_(39b) are each independently the same as described in connection with R₃ in claim 1, a32 is an integer from 0 to 2, a33 is an integer from 0 to 3, a34 is an integer from 0 to 4, a35 is an integer from 0 to 5, and *, *′, and *″ each indicate a binding site to a neighboring atom.
 12. The organometallic compound of claim 1, wherein a moiety represented by

in Formula 1 is selected from groups represented by Formulae CY4-1 to CY4-26:

wherein, in Formulae CY4-1 to CY4-26, X₄ and R₄ are each independently the same as described in claim 1, X₄₉ is C(R_(49a))(R_(49b)), N[(L₄₉)_(b49)-(R₄₉)_(c49)], O, S, or Si(R_(49a))(R_(49b)), L₄₉, b49, R₄₉, and c49 are each independently the same as described in connection with L₄, b4, R₄, and c4 in claim 1, R₄₁ to R₄₈, R_(49a), and R_(49b) are each independently the same as described in connection with R₄ in claim 1, a42 is an integer from 0 to 2, a43 is an integer from 0 to 3, a44 is an integer from 0 to 4, a45 is an integer from 0 to 5, a46 is an integer from 0 to 6, and * and *′ each indicate a binding site to a neighboring atom.
 13. The organometallic compound of claim 1, wherein a moiety represented by

in Formula 1 is selected from groups represented by Formulae CY1(1) to CY1(11), a moiety represented by

in Formula 1 is selected from groups represented by Formulae CY3(1) to CY3(12), and a moiety represented by

in Formula 1 is selected from groups represented by Formulae CY4(1) to CY4(19):

wherein, in Formulae CY1(1) to CY1(11), CY3(1) to CY3(12), and CY4(1) to CY4(19), X₁₉ is C(R_(19a))(R_(19b)), N[(L₁₉)_(b19)-(R₁₉)_(c19)], O, S, or Si(R_(19a))(R_(19b)), X₃₉ is C(R_(39a))(R_(39b)), N[(L₃₉)_(b39)-(R₃₉)_(c39)], O, S, or Si(R_(39a))(R_(39b)), Y₁, R₁, X₃, R₃, X₄, and R₄ are each independently the same as described in claim 1, L₁₉, b19, R₁₉, and c19 are each independently the same as described in connection with L₁, b1, R₁, and c1 in claim 1, L₃₉, b39, R₃₉, and c39 are each independently the same as described in connection with L₃, b3, R₃, and c3 in claim 1, R_(1a), R_(1b), R_(19a), and R_(19b) are each independently the same as described in connection with R₁, R_(3a) to R_(3d), R_(39a), and R_(39b) are each independently the same as described in connection with R₃, R_(4a) to R_(4d) are each independently the same as described in connection with R₄, and *, *′, and *″ each indicate a binding site to a neighboring atom.
 14. The organometallic compound of claim 1, wherein the organometallic compound is represented by Formula 1-1:

wherein, in Formula 1-1, M, X₁ to X₄, Y₁ to Y₁₁, CY₁ to CY₅, T₁, T₂, n1, n2, X₅₁, L₁ to L₄, b1 to b4, R₁ to R₄, c1 to c4, and a1 to a4 are each independently the same as described in claim 1, CY₆ and CY₇ are each independently a C₅-C₃₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, T₄ is C, Si, or Ge, T₅ is selected from a single bond, *—N[(L₉)_(b9)-(R₉)]—*′, *—B(R₉)—*′, *—P(R₉)—*′, *—C(R₉)(R₁₀)—*′, *—Si(R₉)(R₁₀)—*′, *—Ge(R₉)(R₁₀)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)2—*′, *—C(R₉)═*′, *═C(R₉)—*′, *—C(R₉)═C(R₁₀)—*′, *—C(═S)—*′, and *—C≡C—*′, L₆₁ and L₇₁ are each independently the same as described in connection with L₁ in claim 1, b61 and b71 are each independently the same as described in connection with b1 in claim 1, R₆₁ and R₇₁ are each independently the same as described in connection with R₁ in claim 1, c61 and c71 are each independently the same as described in connection with c1 in claim 1, a61 and a71 are each independently the same as described in connection with a1 in claim 1, L₉, b9, and R₉ are each independently the same as described in connection with L₅, b5, and R₅ in claim 1, and * and *′ each indicate a binding site to a neighboring atom.
 15. The organometallic compound of claim 1, wherein the organometallic compound is one of Compounds 1 to 143:


16. An organic light-emitting device comprising: a first electrode; a second electrode; and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer comprises an emission layer and at least one of the organometallic compound of claim
 1. 17. The organic light-emitting device of claim 16, wherein the first electrode is an anode, the second electrode is a cathode, the organic layer further comprises a hole transport region disposed between the first electrode and the emission layer and an electron transport region disposed between the emission layer and the second electrode, the hole transport region comprises a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof, and the electron transport region comprises a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.
 18. The organic light-emitting device of claim 16, wherein the emission layer comprises the organometallic compound.
 19. The organic light-emitting device of claim 18, wherein the emission layer further comprises a host, and an amount of the host is larger than an amount of the organometallic compound.
 20. A diagnostic composition comprising at least one of the organometallic compound of claim
 1. 